AU Falcon revving up by itself

[au1985]

My AU Falcon has started this new thing of revving up itself, what really brought it to my attention was when I was creeping along slowly into a parking space and the car just jolted forward (and i definitely didnt touch the accelerator lol), it doesnt rev up very far just maybe a little over 1000rpm but it does move the car forward quite a bit (also happens in reverse), I can also feel it trying to do it when the brake pedal is depressed, it can come a little shock if and a little dangerous if someone didnt know about it, I'm totally baffled by this so any help would be greatly appreciated

Thanks